From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2F22FE7AD7E for ; Tue, 3 Oct 2023 16:55:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240545AbjJCQzj (ORCPT ); Tue, 3 Oct 2023 12:55:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47630 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240536AbjJCQzg (ORCPT ); Tue, 3 Oct 2023 12:55:36 -0400 Received: from wnew1-smtp.messagingengine.com (wnew1-smtp.messagingengine.com [64.147.123.26]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E4778FB for ; Tue, 3 Oct 2023 09:55:29 -0700 (PDT) Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailnew.west.internal (Postfix) with ESMTP id 66DFB2B0020A; Tue, 3 Oct 2023 12:55:24 -0400 (EDT) Received: from imap51 ([10.202.2.101]) by compute5.internal (MEProxy); Tue, 03 Oct 2023 12:55:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arndb.de; h=cc :cc:content-type:content-type:date:date:from:from:in-reply-to :in-reply-to:message-id:mime-version:references:reply-to:sender :subject:subject:to:to; s=fm1; t=1696352123; x=1696359323; bh=bM N3ahYNWDfnd39aNSh3WGWAh25s8Cnm4TD3ZVFC+Qc=; b=srXfPsAwKo7LL9NfzZ ZItCto4wxQFdX2Ds/QUIfXcIE68COCFLlMXykreKXi75ko4ATOQbJvAGslC8kSuZ wNtj+47ZX6iCzbpT1jEuOXWHD5ZyBGvYKs+pUETvCJ12NkEnZHiweqIjRI/yWhc4 ljwntdK0mND7A0Gn/3Kr9JCfJNZ7rf9F0CsEXEY1SoniFgkPLZD+FrezdVP+3dDZ YdgCxQKY8bSbX6+YutOAJhlELThomcIbwa/alKeicNv4Wq/40uqjQlOx89o6mYX3 OFOWaLXQExfvNxdFGryYmNJ+5/4yKUy33Vsz/t+SC68okj9ywHR1yme0w/ZQ3NV0 a3eA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm2; t=1696352123; x=1696359323; bh=bMN3ahYNWDfnd 39aNSh3WGWAh25s8Cnm4TD3ZVFC+Qc=; b=EcUcSEYhWMQwyrhir+g5g31Hgm39M EWL5N9E+aQSymOo0iJYm4k87C7EHcOKm4X0omB5xbtPFD+TX575loxNOIqJUOh9e qI0jdEqmGjyZmbUF0LagoGQAe2phUR+4BpXikHJ6Emd8nLjqKisBsNo2lVR3IIiG r6BoDO4JV+BIxq02KEwDaj8OqpfPhPpVQB5Vc2EJEcjsVRqVRKwYXurljWVWHgoz DCuFq+Os6TmEtMV18PFTi15Zso9YytX7/ZjKbu1QnVAPti01It3iIOyQ7K8aiB59 oAUwH8ZTZHa01rpn6ANpn/SsKh2cmMiED/QK5nDTh6LKCYWxdMS74zwEg== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvkedrfeejgdduhecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefofgggkfgjfhffhffvvefutgesthdtredtreertdenucfhrhhomhepfdetrhhn ugcuuegvrhhgmhgrnhhnfdcuoegrrhhnugesrghrnhgusgdruggvqeenucggtffrrghtth gvrhhnpeevhfffledtgeehfeffhfdtgedvheejtdfgkeeuvefgudffteettdekkeeufeeh udenucffohhmrghinhepkhgvrhhnvghlrdhorhhgnecuvehluhhsthgvrhfuihiivgeptd enucfrrghrrghmpehmrghilhhfrhhomheprghrnhgusegrrhhnuggsrdguvg X-ME-Proxy: Feedback-ID: i56a14606:Fastmail Received: by mailuser.nyi.internal (Postfix, from userid 501) id 48524B60089; Tue, 3 Oct 2023 12:55:21 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.9.0-alpha0-958-g1b1b911df8-fm-20230927.002-g1b1b911d MIME-Version: 1.0 Message-Id: <231994b0-ca11-4347-8d93-ce66fdbe3d25@app.fastmail.com> In-Reply-To: <487836fc-7c9f-2662-66a4-fa5e3829cf6b@intel.com> References: <20230914185804.2000497-1-sohil.mehta@intel.com> <487836fc-7c9f-2662-66a4-fa5e3829cf6b@intel.com> Date: Tue, 03 Oct 2023 18:54:59 +0200 From: "Arnd Bergmann" To: "Sohil Mehta" , linux-api@vger.kernel.org, Linux-Arch Cc: "Richard Henderson" , "Ivan Kokshaysky" , "Matt Turner" , "Russell King" , "Catalin Marinas" , "Will Deacon" , "Geert Uytterhoeven" , "Michal Simek" , "Thomas Bogendoerfer" , "James E . J . Bottomley" , "Helge Deller" , "Michael Ellerman" , "Nicholas Piggin" , "Christophe Leroy" , "Heiko Carstens" , "Vasily Gorbik" , "Alexander Gordeev" , "Christian Borntraeger" , "Sven Schnelle" , "Yoshinori Sato" , "Rich Felker" , "John Paul Adrian Glaubitz" , "David S . Miller" , "Andy Lutomirski" , "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "Dave Hansen" , x86@kernel.org, "H. Peter Anvin" , "Chris Zankel" , "Max Filippov" , "Peter Zijlstra" , "Arnaldo Carvalho de Melo" , "Mark Rutland" , "Alexander Shishkin" , "Jiri Olsa" , "Namhyung Kim" , "Ian Rogers" , "Adrian Hunter" , "Lukas Bulwahn" , "Sergei Trofimovich" , "Andrew Morton" , "Rohan McLure" , "Andreas Schwab" , "Eric W. Biederman" , "Brian Gerst" , "Randy Dunlap" , "Rick Edgecombe" , "Mark Brown" , "Deepak Gupta" , linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: Re: [PATCH v2] arch: Reserve map_shadow_stack() syscall number for all architectures Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-m68k@vger.kernel.org On Tue, Oct 3, 2023, at 18:35, Sohil Mehta wrote: > On 9/14/2023 11:58 AM, Sohil Mehta wrote: >> commit c35559f94ebc ("x86/shstk: Introduce map_shadow_stack syscall") >> recently added support for map_shadow_stack() but it is limited to x86 >> only for now. There is a possibility that other architectures (namely, >> arm64 and RISC-V), that are implementing equivalent support for shadow >> stacks, might need to add support for it. >> >> Independent of that, reserving arch-specific syscall numbers in the >> syscall tables of all architectures is good practice and would help >> avoid future conflicts. map_shadow_stack() is marked as a conditional >> syscall in sys_ni.c. Adding it to the syscall tables of other >> architectures is harmless and would return ENOSYS when exercised. >> >> Note, map_shadow_stack() was assigned #453 during the merge process >> since #452 was taken by fchmodat2(). >> >> For Powerpc, map it to sys_ni_syscall() as is the norm for Powerpc >> syscall tables. >> >> For Alpha, map_shadow_stack() takes up #563 as Alpha still diverges from >> the common syscall numbering system in the other architectures. >> >> Link: https://lore.kernel.org/lkml/20230515212255.GA562920@debug.ba.rivosinc.com/ >> Link: https://lore.kernel.org/lkml/b402b80b-a7c6-4ef0-b977-c0f5f582b78a@sirena.org.uk/ >> >> Signed-off-by: Sohil Mehta >> --- > > Gentle ping... > > Are there any additional comments? It applies cleanly on 6.6-rc4. > > Or does it seem ready to be merged? It has the following > acknowledgements until now: > > Reviewed-by: Rick Edgecombe > Acked-by: Michael Ellerman (powerpc) > Reviewed-by: Arnd Bergmann If you like, I can pick this up for 6.7 through the asm-generic tree. If you think this should be part of 6.6, I would suggest to merge it through the tree that originally contained the syscall code. Arnd